<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- 第一种方式: 使用的是style标签 -->
    <style type="text/less">
        .box1 {
            width: 400px;
            height: 400px;
            background-color: orange;
            .box2 {
                width: 200px;
                height: 200px;
                background-color: purple;
            }
        }
    </style>
</head>
<body>
    <div class="box1">
        <div class="box2"></div>
        <script src="./js/less.js"></script>
    </div>
</body>
</html>